Catalyst composition for preparing olefin polymers

ABSTRACT

A catalyst composition for preparing olefin polymers. The catalyst composition includes a metallocene compound and an activating cocatalyst. In the metallocene compound, two cyclopentadienyl groups are bridged by X (carbon, silicon, germanium or tin) in a ring structure. The bite angle 0 formed by the two cyclopentadienyl rings and X is equal to or greater than 100 degrees. The obtained olefin polymer has high cycloolefin conversion and a high glass transition temperature. In addition, the catalyst composition can still maintain relatively high activity at high temperature reaction conditions.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of application Ser.No. 09/559,976 filed on Apr. 27, 2000, now pending

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a catalyst composition forpreparing olefin polymers, and more particularly to a catalystcomposition for preparing cycloolefin copolymers with a high cycloolefinconversion and a high glass transition temperature. The catalystcomposition can still maintain relatively high activity at hightemperature reaction conditions.

[0004] 2. Description of the Prior Art

[0005] Olefin-based polymers have been used in a wide range ofapplications. One group of commonly used olefin-based polymers ispolyolefins, that is, homopolymers or copolymers of olefins. Thesepolyolefin polymers are typically used in such applications as blow andinjection molding, extrusion coating, film and sheeting, pipe, wire andcable.

[0006] An example of polyolefin is ethylene-propylene elastomer(ethylene-propylene rubbers, EPR). It has many end-use applications dueto its resistance to weather, good heat aging properties and its abilityto be compounded with large quantities of fillers and plasticizers.Typical automotive uses are radiator and heater hoses, vacuum tubing,weather stripping and sponge doorseals. Typical industrial uses aresponge parts, gaskets and seals.

[0007] Another group of commonly used olefin-based polymers iscycloolefin copolymers (COC). One of the examples is a copolymer ofcycloolefin and ethylene, which has an extraordinarily high glasstransition temperature compared with traditional polyolefins owing toits incorporation of cyclic monomers. Also, the polymer has hightransparency in physical properties due to reduced crystallinity by theincorporation of cyclic monomers. The combination of light transparency,heat resistance, aging resistance, chemical resistance, solventresistance, and low dielectric constant makes COC a valuable materialthat has attracted research activities in both academic and industrialsectors. Currently, ethylene/cycloolefin copolymers have beendemonstrated to be a suitable material in the field of optical materialssuch as optical memory disks and optical fibers.

[0008] Ethylene/cycloolefin copolymers are usually prepared in thepresence of metallocene/aluminoxane catalyst systems, as described inU.S. Pat. No. 5,559,199 (Abe et al.) and U.S. Pat. No. 5,602,219(Aulbach et al.) In U.S. Pat. No. 5,559,199, metallocenes such asisopropylidene (cyclopentadienylmethylcyclopentadienyl)zirconiumdichloride are disclosed. In U.S. Pat. No. 5,602,219, metallocenes suchas dimethylsilyl-(1-indenyl)-cyclopentadienylzirconium dichloride aredisclosed.

[0009] However, conventional processes for preparingethylene-cycloolefin copolymers have some common problems. First, theconversion of the cycloolefin (or the incorporation of the cycloolefin)is too low. Second, the high incorporation of ethylene results in toolow a glass transition temperature (Tg) of the copolymer.

[0010] To increase the conversion of the cycloolefin, a common techniqueis to increase the reaction temperature or reducing reaction pressure ofethylene. However, using this technique, the reactivity for theproduction of cycloolefin polymer will be reduced as the examples showin U.S. Pat. Nos. 5,602,219 and 5,559,199. Obviously, this techniquewill reduce the commercial feasibility for COC polymerization.Therefore, efforts to enhance the reactivity of catalyst for increasingthe incorporation of cyclic olefins during the COC polymerizationprocesses are highly desirable in the industrial applications.

SUMMARY OF THE INVENTION

[0011] An object of the present invention is to provide a catalystcomposition for preparing olefin polymers, particularly for preparing(ethylene/cycloolefin copolymers with high cycloolefin incorporation anda high Tg.

[0012] To achieve the above-mentioned object, the catalyst compositionof the present invention catalyst composition for preparing an olefinpolymer includes (a) a metallocene compound represented by formula (I)and (b) an activating cocatalyst.

[0013] Formula (I) has the structure

[0014] wherein

[0015] R¹ can be the same or different and is hydrogen, halogen, analkyl, alkenyl, aryl, alkylaryl or arylalkyl group having from 1 to 20carbon atoms, or two adjacent R¹ groups can link together with thecarbon atoms to which they are attached to form a saturated orunsaturated ring system having from 4 to 20 carbon atoms;

[0016] R² can be the same or different and has the same definition asR¹;

[0017] X is carbon, silicon, germanium or tin;

[0018] n is 2 to 12;

[0019] R³ and R⁴ can be the same or different and are hydrogen, halogen,an alkyl, alkenyl, aryl, alkylaryl or arylalkyl group having from 1 to12 carbon atoms;

[0020] M is a Group IVB transition metal with an oxidation state of +4;

[0021] Y is the same or different and is independently an anionic ligandwith a −1 valence; and

[0022] the angle θ formed by the two cyclopentadienyl rings and X isequal to or greater than 100 degrees.

[0023] In formula (I) , X is preferably carbon or silicon, and n ispreferably 2, 3 or 4.

[0024] The activating cocatalyst can be (1) an aluminoxane, (2) amixture of AlR¹¹R¹²R¹³ and a borate, or (3) a mixture of AlR¹¹R¹²R¹³ andan aluminoxane, wherein R¹¹, R¹² and R¹³ are a C₁₋₂₀ aliphatic group ora C₆₋₁₀ aromatic group.

[0025] The catalyst composition of the present invention can be used toprepare an olefin polymer. Using the catalyst composition to prepare acycloolefin copolymer, the cycloolefin incorporation is increased, andthe copolymer obtained has a high glass transition temperature rangingfrom 60° C.-350° C.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is an X-ray crystal structure of the metallocene compoundprepared from Catalyst Example 5 of the present invention.

[0027]FIG. 2 is an X-ray crystal structure of the metallocene compoundprepared from Catalyst Example 6 of the present invention.

[0028]FIG. 3 is an X-ray crystal structure of the metallocene compoundprepared from Catalyst Example 7 of the present invention.

[0029]FIG. 4 is an X-ray crystal structure of the metallocene compoundprepared from Comparative Catalyst Example 8 of the present invention.

[0030]FIG. 5 is an X-ray crystal structure of the metallocene compoundprepared from Comparative Catalyst Example 9 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0031] The present invention provides a catalyst composition forpreparing olefin polymers, which includes a metallocene compoundrepresented by formula (I) and an activating cocatalyst.

[0032] One aspect of the present invention resides in that X (Group IVAelement such as C) in formula (I) is bridged by —(CR³R⁴)_(n)— to form athree-, four-, or five-member ring structure, wherein n is 2, 3 or 4.Thus, the angle θ formed by the two cyclopentadienyl rings and X isequal to or greater than 100 degrees.

[0033] Referring to the conventional metallocenes for preparingcycloolefin copolymers in U.S. Pat. Nos. 5,559,199 (U.S. Pat. No. '199)and No. 5,602,219 (U.S. Pat. No. '219) as mentioned above, for example,isopropylidene(cyclopenta-dienylfluorenyl)zirconium dichloride anddimethylsilyl-(1-indenyl)cyclopentadienylzirconium dichloride, it can beseen that two methyl groups are bonded to the carbon or silicon atom ofthe metallocene. Part of the chemical structure of the metallocene isdepicted in the Table 1 for better understanding, in which Cp indicatesunsubstituted or substituted cyclopentadienyl, and θ₁, θ₂, and θ₃,indicate the angle formed by Cp, Group IVA element, and another Cp(Cp-IVA-Cp), which is called the bite angle. TABLE 1 U.S. ′199 (biteU.S. ′219 (bite Present invention angle's X-ray data, angle's X-raydata, (bite angle, see Journal of see Organometallic see FIG. 1 andOrganometallic 1994, 13, 964 and Table 2) vide infra Chemistry Journalof 1995, 497, 105). Organometallic Chemistry 1989, 369, 359).

[0034] In contrast with the metallocene of U.S. Pat. No. '199 and U.S.Pat. No. '219, the Group IVA element such as carbon is bridged by—(CR³R⁴)_(n)— (n=2, 3 or 4) to form a ring structure in the presentinvention. As a result of this bridging, the angle formed by Cp-IVA-Cpcan be enlarged. That is to say, angle θ₃ is larger than both θ₁ and θ₂.It should be noted that to date, metallocene catalysts containing a biteangle larger than 100 degrees have never been reported from prior art.

[0035] When a conventional metallocene compound is used as a catalyst toprepare a copolymer of a cycloolefin and an acyclic olefin (such asethylene), since the bite angle is is small, it is difficult for thecycloolefin that has a larger size than ethylene to approach themetallocene's active site. Thus, an undesired low incorporation amountof the cycloolefin occurs in the copolymer produced. However, when themetallocene compound of the present invention is used as the catalyst,the larger bite angle leads to a greater vacancy around themetallocene's active site. Thereby the larger sized cycloolefin hasgreater probability to approach the reactive site. Consequently,copolymers produced using the catalyst composition of the presentinvention tend to have a higher cycloolefin incorporation in the polymerbackbone, thus significantly increasing their glass transitiontemperatures (Tg).

[0036] The scientific basis is explained as follows. In a bridgedmetallocene of the present invention, when the bite angle between two Cprings opens up, the active center of the metal moves outward. This willsubstantially increase the ratio of the coordination speed of acycloolefin to acyclic olefin monomer with the active center of thecatalyst compared with other catalysts, which increases the ratio of thecycloolefin relative to acyclic olefin monomer incorporated in theresulting copolymer in turn. The Tg of the copolymer increasesaccordingly, and the polymerization activity also increases. It shouldbe noted that in a bridged metallocene catalyst, the bite angleresulting from a carbon bridge is obviously larger than that from asilicon bridge. One reason is that the element radius of carbon (0.77 Å)is smaller than that of silicon (1.11 Å). The other reason is that theelectronegativity of carbon (2.5) is larger than that of silicon (1.8),thus carbon-carbon has a far larger bonding energy than silicon-carbon.Therefore, when Cp is bridged with a group IVA element, the siliconbridge has a larger degree of deformation than carbon, resulting in asmaller bite angle.

[0037] In formula (I), when R¹ and R² are an alkyl, alkenyl, aryl,alkylaryl or arylalkyl group having from 1 to 20 carbon atoms,preferably from 1 to 15 carbon atoms, they are preferably C₁₋₁₀ alkyl,C₁₋₁₀ alkenyl, C₆₋₁₀ aryl, C₇₋₁₀ alkylaryl, and C₇₋₁₀ arylalkyl.Representative examples of R¹ and R² include H, methyl, ethyl, propyl,butyl, isobutyl, amyl, isoamyl, hexyl, 2-ethylhexyl, heptyl, octyl,vinyl, allyl, isopropenyl, phenyl, and tolyl.

[0038] When two adjacent R¹ (or R²) groups link together with the carbonatoms to which they are attached to form a ring system having from 4 to20 carbon atoms, preferably 4 to 6 carbon atoms, R¹ (or R²) can formwith the cyclopentadienyl moiety to which they are attached a saturatedor unsaturated polycyclic cyclopentadienyl ring such as an indenyl,tetrahydroindenyl, fluorenyl or octahydrofluorenyl group. Representativeexamples of such rings include η⁵-cyclopentadienyl,η⁵-methylcyclopentadienyl, η⁵-ethylcyclopentadienyl,η⁵-propylcyclopentadienyl, η⁵-tetramethylcyclopentadienyl,η⁵-pentamethylcyclopentadienyl, η⁵-n-butylcyclopenta-dienyl, indenyl,tetrahydroindenyl, fluorenyl, and octahydrofluorenyl.

[0039] Y can be H, a C₁₋₂₀ hydrocarbon group, a halogen, C₆₋₂₀ aryl,C₇₋₂₀ alkylaryl or arylalkyl, C₁₋₂₀ alkoxy, C₁₋₂₀ aryloxy, NH₂, NHR⁷,NR⁷R⁸, —(C═O)NH₂, —(C═O)NHR⁹, —(C═O)NR⁹R¹⁰, each of R⁷, R⁸, R⁹ and R¹⁰being C₁₋₂₀ hydrocarbyl. Suitable Y groups include methyl, ethyl,phenyl, chlorine, bromine, methoxy, ethoxy, —NH₂, —NH(CH₃), —N(CH₃)₂,—N(C₂H₅)₂, and —N(C₃H₇)₂.

[0040] In the present invention, the metallocene compound represented byformula (I) can be combined with an activating coatalyst to form acatalyst composition, which can be used for preparing olefin polymers.

[0041] The cocatalyst used in the present invention can be (1) analuminoxane, (2) a mixture of AlR¹¹R¹²R¹³ and a borate, or (3) a mixtureof AlR¹¹R¹²R¹³ and an alumoxane. R¹¹, R¹², and R¹³ are a C₁₋₂₀ aliphaticgroup or a C₆₋₁₀ aromatic group. A preferred aluminoxane is methylaluminoxane. Representative examples of AlR¹¹R¹²R¹³ include trimethylaluminum, triethyl aluminum, tripropyl aluminum, trisopropyl aluminum,tributyl aluminum, and triisobutyl aluminum (TIBA). Representativeexamples of borates include N,N-dimethyl aniliniumtetrakis(pentafluorophenyl)borate, triphenyl carbeniumtetrakis(pentafluorophenyl)borate, trimethyl ammoniumtetrakis(pentafluorophenyl)borate, ferroceniumtetrakis(pentafluorophenyl)borate, dimethyl ferroceniumtetrakis(pentafluorophenyl)borate, and silvertetrakis(pentafluorophenyl)borate.

[0042] Using the catalyst composition of the present invention, anolefin polymer can be synthesized. In the presence of a catalyticallyeffective amount of the catalyst composition of the present inventionunder polymerizing conditions, an olefin monomer can be subjected topolymerization (homopolymerization), or at least one olefin monomertogether with at least one other monomer can be subjected topolymerization (copolymerization).

[0043] According to the present invention, a preferred olefin is acycloolefin. Preferably, the polymerization of the present invention ishomopolymerization of a cycloolefin, or copolymerization of acycloolefin and an acycloolefin.

[0044] Cycloolefins suitable for use in the present invention include abicycloheptene, a tricyclodecene, a tricycloundecene, atetracyclododecene, a pentacyclopentadecene, a pentacyclopentadecadiene,a pentacyclohexadecene, a hexacycloheptadecene, a heptacycloeicosene, aheptacycloheneicosene, an octacyclodocosene, a nonacyclopentacosene, anda nonacyclohexacosene. Representative examples include norbornene,tetracyclododecene, dicyclopentadiene, and ethylidene norbornene.

[0045] Suitable acyclic olefins can be ethylene or α-olefins.Representative examples of α-olefins include those olefins having 3 to12 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, and1-octene.

[0046] More particularly, the catalyst composition of the presentinvention can be advantageously used to prepare acylicolefin/cycloolefin copolymers, such as ethylene/cycloolefin copolymers.By means of the specific catalyst composition, the ethylene/cycloolefincopolymer obtained will have a high cycloolefin conversion and a highTg.

[0047] By means of the specific catalyst composition of the presentinvention, the resulting olefin polymer has a glass transitiontemperature ranging from 60-350° C., preferably 120-350° C., mostpreferably 250-350° C.

[0048] The novel catalyst composition disclosed in the present inventioncan be used in slurry reactions, gas phase reactions, and solutionpolymerization reactions. According to the experimental results of thepresent invention, it can be proved that the specific catalystcomposition of the present invention can still have superior activity ata higher reaction temperature. Such superior activity will lead to theincrease of the cycloolefin incorporation amount, and the cycloolefincopolymer obtained will have an increased Tg, which can not be achievedby a conventional similar catalyst.

[0049] According to the present invention, representative examples ofthe metallocene compound of formula (I) include the following formulae:

[0050] wherein R is a C₁-C₂₀ hydrocarbyl group,

[0051] wherein R is a C₁-C₂₀ hydrocarbyl group,

[0052] wherein R is a C₁-C₂₀ hydrocarbyl group,

[0053] wherein A is halogen,

[0054] wherein R is a C₁-C₂₀ hydrocarbyl group,

[0055] wherein R is a C₁₋₂₀ hydrocarbyl group,

[0056] wherein A is halogen, and

[0057] wherein A is halogen.

[0058] The following examples are intended to illustrate the process andthe advantages of the present invention more fully without limiting itsscope, since numerous modifications and variations will be apparent tothose skilled in the art. Unless otherwise indicated, all parts,percents, ratios and the like are by weight.

[0059] Synthesis of Metallocene

CATALYST EXAMPLE 1

[0060] Synthesis of 1-cyclopentadienyl-1-indenylcyclobutane (a bridgedcyclopentadiene)

[0061] Indene (5.8 g, 50 mmole) was placed in a 250 ml round bottomflask with 50 ml of THF (tetrahydrofuran). 40 ml (1.6 M, 64 mmole) ofn-butyl lithium (n-BuLi) was is added into the solution under an icebath. The mixture turned orange red. The ice bath was removed and themixture was stirred for 3 hours. Then, the reaction mixture was strippedunder vacuum to remove solvent, washed with 50 ml of pentane to removeexcess n-BuLi, and filtered to collect the precipitate.

[0062] The precipitate was dissolved in 50 ml of THF and6,6-trimethylenefulvene (5.9 g, 50 mmole) was added gradually to thesolution under an ice bath. After stirring for 24 hours, 1 ml of waterwas added to the mixture to terminate the reaction. The reaction mixturewas stripped under vacuum to remove solvent, dissolved with 100 ml ofhexane, and filtered to collect the filtrate. The crude product (i.e.,filtrate) was purified by column chromatography (the packing was 20 g ofsilica gel, the eluent was 100% hexane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (8.2g, yield=70%).

CATALYST EXAMPLE 2

[0063] Synthesis of 1-methylcyclopentadienyl-1-indenyl-cyclobutane

[0064] Indene (2.9 g, 25 mmole) was placed in a 250 ml round bottomflask with 30 ml of THF (tetrahydrofuran). 20 ml (1.6 M, 32 mmole) ofn-butyl lithium (n-BuLi) was added into the solution under an ice bath.The mixture turned orange red. The ice bath was removed and the mixturewas stirred for 3 hours. Then, the reaction mixture was stripped undervacuum to remove solvent, washed with 50 ml of pentane to remove excessn-BuLi, and filtered to collect the precipitate.

[0065] The precipitate was dissolved in 30 ml of THF and3-methyl-6,6-trimethylenefulvene (3.3 g, 25 mmole) was added graduallyto the solution under an ice bath. After stirring for 24 hours, 1 ml ofwater was added to the mixture to terminate the reaction. The reactionmixture was stripped under vacuum to remove solvent, dissolved with 50ml of hexane, and filtered to collect the filtrate. The crude product(i.e., filtrate) was purified by column chromatography (the packing was20 g of silica gel, the eluent was 100% hexane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (4.7g, yield=75.8%).

CATALYST EXAMPLE 3

[0066] Synthesis of cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0067] 1-Cyclopentadienyl-1-indenylcyclobutane (0.94 g, 4 mmole)obtained as in Catalyst Example 1 and Zr(NMe₂)₄ (1 g, 3.7 mmole) wereplaced in a 100 ml round bottle flask. 20 ml of toluene was added to theflask and the mixture was allowed to react at room temperature for 15hours. The reaction mixture was stripped under vacuum to remove solventand then 50 ml of pentane was added to dissolve the residue. Thesolution was filtered and the filtrate was then concentrated to obtain ayellow solid (1.45 g, yield=95%).

CATALSYT EXAMPLE 4

[0068] Synthesis of cyclobutylidene(1-η⁵-methylcyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0069] 1-Methylcyclopentadienyl-1-indenylcyclobutane (0.99 g, 4 mmole)obtained as in Catalyst Example 2 and Zr(NMe₂)₄ (1 g, 3.7 mmole) wereplaced in a 100 ml round bottle flask. 20 ml of toluene was added to theflask and the mixture was allowed to react at room temperature for 15hours. The reaction mixture was stripped under vacuum to remove solventand then 50 ml of pentane was added to dissolve the residue. Thesolution was filtered and the filtrate was then concentrated to obtain ayellow solid (1.54 g, yield=98%).

CATALYST EXAMPLE 5

[0070] Synthesis of cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-fluorenyl)zirconium dichloride

[0071] 1-cyclopentadienyl-1-fluorenylcyclobutane was prepared by similarprocedures as described in Catalyst Example 1. The resulting substance(1.14 g, 4 mmole) was combined in toluene with Zr(NMe₂)₄ (1 g, 3.7mmole) within a 100 ml round bottle flask. 20 ml of toluene was added tothe flask and the mixture was allowed to react at room temperature for15 hours for providing the metallocene amide complex. The resultingsolution was then treated with 1.05 ml of trimethylsilylchloride. Theresulting solution was then allowed to react at room temerature for 6 hrto privide a yellow precipitate ofcyclobutylidene(1-η⁵-cyclopentadienyl) (1-η⁵-fluorenyl)zirconiumdichloride (1.15 g, 62% yield).

[0072] The precipitating powder of the catalyst was then recrystallizedover toluene to form an X-ray quality single crystalline catalyst. X-raycrystal data and structural refinement were recorded by a Nonius Kappaccd diffractometer at 295 K. Crystal data and structure refinement forthe product cyclobutylidene(1-η⁵-cyclopentadienyl) (1-η⁵-fluorenyl)zirconium dichloride (labeled to IC 8359) is shown in Table 2attached. Selected bond lengths and bond angles are listed in Table 3attached. X-ray crystal structure is shown in FIG. 1. The resultsclearly indicate that a novel catalyst with exceptional large bite angle(100.8°) was obtained in the system.

CATALYST EXAMPLE 6

[0073] Synthesis of cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconium dichloride

[0074] (1) 6,6-trimethylenefulvene (Catalyst A)

[0075] 5 g of cyclobutanone (71 mmol) and 14.35 ml of cyclopentadiene(175 mmol) were charged in a 300 ml reaction bottle. 70 ml of CH₃OH wasadded as a solvent. Then, 8.75 ml of pyrrolidine (105 mmol) was addedgradually and the mixture was stirred at room temperature for 30minutes. Next, 6.3 ml of CH₃COOH (105 mmol) was added gradually andstirred for 10 minutes. 200 ml of H₂O and 200 ml of pentane were usedfor extraction. The upper pentane portion was collected. The lower waterportion was further extracted with pentane three times. The collectedpentane portion was dehydrated with MgSO₄, held still for 30 minutes,filtered, and concentrated under reduced pressure to afford a yellowliquid product (5.5 g, yield=68.9%).

[0076] (2) 1-cyclopentadienyl-1-indenylcyclobutane

[0077] Indene (5.8 g, 50 mmole) was placed in a 250 ml round bottomflask with 50 ml of THF (tetrahydrofuran). 34.3 ml (1.6 M, 55 mmole) ofn-butyl lithium (n-BuLi) was added into the solution under an ice bath.The mixture turned orange red. The ice bath was removed and the mixturewas stirred for 3 hours. 5.4 g of 6,6-trimethylenefulvene (46 mmole) wasadded gradually to the mixture. After stirring for 24 hours, 1 ml ofwater was added to the mixture to terminate the reaction. The reactionmixture was stripped under vacuum to remove solvent, washed with 100 mlof pentane, and filtered to remove the salt. The crude product (i.e.,filtrate) was purified by column chromatography (the packing was 20 g ofsilica gel, the eluent was 100% pentane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (6.96g, yield=65%).

[0078] (3)cyclobutylidene(1-η⁵cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0079] 1 g of 1-Cyclopentadienyl-1-indenylcyclobutane (4.3 mmol)obtained and Zr(NMe₂)₄ (1.06 g, 4.0 mmol) were placed in a 100 ml roundbottle flask. 50 ml of toluene was added to the flask and the mixturewas allowed to react for 24 hours. The reaction mixture was strippedunder vacuum to remove solvent and then 20 ml of pentane was added todissolve the residue. The solution was filtered and the filtrate wasthen concentrated to obtain an orange yellow solid (1.47 g,yield=89.3%).

[0080] (4) cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride

[0081] 0.5 g of cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium (1.2 mmol) was charged in a100 ml round bottle and 20 ml of toluene was added. 0.39 g of (CH₃)₃SiCl(3.6 mmol) was added gradually at room temperature and the mixture wasallowed to react for 24 hours. The reaction mixture stripped undervacuum to remove solvent and washed with pentane several times to removeexcess (CH₃)₃SiCl. The pentane solution was then concentrated to obtaina pale yellow solid (0.4 g, yield=83.5%). X-ray crystal structure of theproduct cyclobutylidene(1-η⁵-cyclopentadienyl) (1-η⁵-indenyl)-zirconiumdichloride is shown in FIG. 2. The results clearly indicate that a novelcatalyst with exceptional large bite angle (100.44°) was obtained in thesystem.

CATALYST EXAMPLE 7

[0082] Synthesis of cyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconium dichloride (Catalyst B)

[0083] (1) 6,6-tetramethylenefulvene

[0084] 6 g of cyclopentanone (71 mmol) and 14.35 ml of cyclopentadiene(175 mmol) were charged in a 300 ml reaction bottle. 70 ml of CH₃OH wasadded as a solvent. Then, 8.75 ml of pyrrolidine (105 mmol) was addedgradually and the mixture was stirred at room temperature for 30minutes. Next, 6.3 ml of CH₃COOH (105 mmol) was added gradually andstirred for 10 minutes. 200 ml of H₂O and 200 ml of pentane were usedfor extraction. The upper pentane portion was collected. The lower waterportion was further extracted with pentane three times. The collectedpentane portion was dehydrated with MgSO₄, held still for 30 minutes,filtered, and concentrated under reduced pressure to afford a yellowliquid product (8.4 g, yield=89%).

[0085] (2) 1-cyclopentadienyl-1-indenylcyclopentane

[0086] Indene (5.8 g, 50 mmole) was placed in a 250 ml round bottomflask with 50 ml of THF (tetrahydrofuran). 34.3 ml (1.6 M, 55 mmole) ofn-butyl lithium (n-BuLi) was added into the solution under an ice bath.The mixture turned orange red. The ice bath was removed and the mixturewas stirred for 3 hours. 6.1 g of 6,6-tetramethylenefulvene (46 mmole)was added gradually to the mixture. After stirring for 24 hours, 1 ml ofwater was added to the mixture to terminate the reaction. The reactionmixture was stripped under vacuum to remove solvent, washed with 100 mlof pentane, and filtered to remove the salt. The crude product (i.e.,filtrate) was purified by column chromatography (the packing was 20 g ofsilica gel, the eluent was 100% pentane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (7.6g, yield=67%).

[0087] (3)cyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0088] 1 g of 1-cyclopentadienyl-1-indenylcyclopentane (4.0 mmol)obtained and Zr(NMe₂)₄ (0.96 g, 3.6 mmol) were placed in a 100 ml roundbottle flask. 50 ml of toluene was added to the flask and the mixturewas allowed to react for 24 hours. The reaction mixture was strippedunder vacuum to remove solvent and then 20 ml of pentane was added todissolve the residue. The solution was filtered and the filtrate wasthen concentrated to obtain an orange yellow solid (1.41 g,yield=90.2%).

[0089] (4) cyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride

[0090] 0.51 g, ofcyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium(1.2 mmol) was charged in a 100 ml round bottle and 20 ml of toluene wasadded. 0.39 g of (CH₃)₃SiCl (3.6 mmol) was added gradually at roomtemperature and the mixture was allowed to react for 24 hours. Thereaction mixture stripped under vacuum to remove solvent and washed withpentane several times to remove excess (CH₃)₃SiCl. The pentane solutionwas then concentrated to obtain a pale yellow solid (0.42 g,yield=85.7%). X-ray crystal structure of the productcyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconiumdichloride is shown in FIG. 3. The results clearly indicate that a novelcatalyst with exceptional large bite angle (101.0°) was obtained in thesystem.

COMPARATIVE CATALYST EXAMPLE 8

[0091] Synthesis of cycloheptylidene (1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconium dichloride (Catalyst C)

[0092] (1) 6,6-hexamethylenefulvene

[0093] 8 g, of cycloheptanone (71 mmol) and 14.35 ml of cyclopentadiene(175 mmol) were charged in a 300 ml reaction bottle. 70 ml of CH₃OH wasadded as a solvent. Then, 8.75 ml of pyrrolidine (105 mmol) was addedgradually and the mixture was stirred at room temperature for 30minutes. Next, 6.3 ml of CH₃COOH (105 mmol) was added gradually andstirred for 10 minutes. 200 ml of H₂O and 200 ml of pentane were usedfor extraction. The upper pentane portion was collected. The lower waterportion was further extracted with pentane three times. The collectedpentane portion was dehydrated with MgSO₄, held still for 30 minutes,filtered, and concentrated under reduced pressure to afford a yellowliquid product (10.6 g, yield=93%).

[0094] (2) 1-cyclopentadienyl-1-indenylcycloheptane

[0095] Indene (5.8 g, 50 mmole) was placed in a 250 ml round bottomflask with 50 ml of THF (tetrahydrofuran). 34.3 ml (1.6 M, 55 mmole) ofn-butyl lithium (n-BuLi) was added into the solution under an ice bath.The mixture turned orange red. The ice bath was removed and the mixturewas stirred for 3 hours. 7.4 g of 6,6-hexamethylenefulvene (46 mmole)was added gradually to the mixture. After stirring for 24 hours, 1 ml ofwater was added to the mixture to terminate the reaction. The reactionmixture was stripped under vacuum to remove solvent, washed with 100 mlof pentane, and filtered to remove the salt. The crude product (i.e.,filtrate) was purified by column chromatography (the packing was 20 g ofsilica gel, the eluent was 100% pentane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (8.6g, yield=67.7%).

[0096] (3) cycloheptylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0097] 1 g of 1-cyclopentadienyl-1-indenylcycloheptane (3.6 mmol)obtained and Zr(NMe₂)₄ (0.86 g, 3.2 mmol) were placed in a 100 ml roundbottle flask. 50 ml of toluene was added to the flask and the mixturewas allowed to react for 24 hours. The reaction mixture was strippedunder vacuum to remove solvent and then 20 ml of pentane was added todissolve the residue. The solution was filtered and the filtrate wasthen concentrated to obtain an orange yellow solid (1.25 g, yield=86%).

[0098] (4) cycloheptylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride

[0099] 0.5 g of cycloheptylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium (1.1 mmol) was charged in a100 ml round bottle and 20 ml of toluene was added. 0.36 g of (CH₃)₃SiCl(3.3 mmol) was added gradually at room temperature and the mixture wasallowed to react for 24 hours. The reaction mixture stripped undervacuum to remove solvent and washed with pentane several times to removeexcess (CH₃)₃SiCl. The pentane solution was then concentrated to obtaina pale yellow solid (0.41 g, yield=85.2%). X-ray crystal structure ofthe product cycloheptylidenel(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride is shown in FIG. 4. The bite angleof the product is 99.8°.

COMPARATIVE CATALYST EXAMPLE 9

[0100] Synthesis of cyclohexylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconium dichloride (Catalyst E)

[0101] (1) 6,6-pentamethylenefulvene

[0102] 7 g of cyclohexanone (71 mmol) and 14.35 ml of cyclopentadiene(175 mmol) were charged in a 300 ml reaction bottle. 70 ml of CH₃OH wasadded as a solvent. Then, 8.75 ml of pyrrolidine (105 mmol) was addedgradually and the mixture was stirred at room temperature for 30minutes. Next, 6.3 ml of CH₃COOH (105 mmol) was added gradually andstirred for 10 minutes. 200 ml of H₂O and 200 ml of pentane were usedfor extraction. The upper pentane portion was collected. The lower waterportion was further extracted with pentane three times. The collectedpentane portion was dehydrated with MgSO₄, held still for 30 minutes,filtered, and concentrated under reduced pressure to afford a yellowliquid product (8.7 g, yield=83.3%).

[0103] (2) 1-cyclopentadienyl-1-indenylcyclohexane

[0104] Indene (5.8 g, 50 mmole) was placed in a 250 ml round bottomflask with 50 ml of THF (tetrahydrofuran). 34.3 ml (1.6 M, 55 mmole) ofn-butyl lithium (n-BuLi) was added into the solution under an ice bath.The mixture turned orange red. The ice bath was removed and the mixturewas stirred for 3 hours. 6.7 g of 6,6-pentamethylenefulvene (46 mmole)was added gradually to the mixture. After stirring for 24 hours, 1 ml ofwater was added to the mixture to terminate the reaction. The reactionmixture was stripped under vacuum to remove solvent, washed with 100 mlof pentane, and filtered to remove the salt. The crude product (i.e.,filtrate) was purified by column chromatography (the packing was 20 g ofsilica gel, the eluent was 100% pentane). The solution was thenconcentrated under reduced pressure to obtain a pale yellow liquid (8.3g, yield=69%).

[0105] (3) cyclohexylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium

[0106] 1 g of 1-cyclopentadienyl-1-indenylcyclohexane (3.8 mmol)obtained and Zr(NMe₂)₄ (0.91 g 3.4 mmol) were placed in a 100 ml roundbottle flask. 50 ml of toluene was added to the flask and the mixturewas allowed to react for 24 hours. The reaction mixture was strippedunder vacuum to remove solvent and then 20 ml of pentane was added todissolve the residue. The solution was filtered and the filtrate wasthen concentrated to obtain an orange yellow solid (1.27 g,yield=84.8%).

[0107] (4) cyclohexylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride

[0108] 0.53 g ofcyclohexylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)bis(dimethylamino)zirconium(1.2 mmol) was charged in a 100 ml round bottle and 20 ml of toluene wasadded. 0.39 g of (CH₃)₃SiCl (3.6 mmol) was added gradually at roomtemperature and the mixture was allowed to react for 24 hours. Thereaction mixture stripped under vacuum to remove solvent and washed withpentane several times to remove excess (CH₃)₃SiCl. The pentane solutionwas then concentrated to obtain a pale yellow solid (0.42 g,yield=82.5%). X-ray crystal structure of the productcyclohexylidene(1-η⁵-cyclopentadienyl) (1-η⁵-indenyl)-zirconiumdichloride is shown in FIG. 5. The bite angle of the product is 97.3°.

[0109] Polymer Synthesis

EXAMPLE A

[0110] Synthesis of Ethylene/Norbornene Copolymer

[0111] Toluene was refluxed in the presence of sodium to remove water toa water content of less than 10 ppm. 500 g of norbornene and 88 g of drytoluene were mixed under nitrogen to obtain an 85 wt % norbornenesolution.

[0112] A 500 ml reactor vessel was heated to 120° C., evacuated for 1hour, and then purged with nitrogen gas three or four times to ensurecomplete removal of moisture and oxygen. Ethylene was introduced intothe reactor to replace nitrogen and expelled. The procedure was repeatedagain. After this, 100 g of the 85 wt % norbornene solution was thencharged in the reactor under a nitrogen atmosphere and the solution wasstirred at a rate of 250 rpm while 4 ml of 1.49 M MAO (methylaluminoxane) was injected into the reactor by a syringe.

[0113] The reactor temperature was adjusted to 100° C. After thetemperature was stabilized, 1 mg of the metallocene complex obtained asin Catalyst Example 3 was dissolved in 1 ml of toluene in a glove box.Then, 3 ml of MAO was added in the metallocene solution for activation.After five minutes of activation, the metallocene solution was theninjected into the reactor to initiate polymerization and the mixture wasstirred at a rate of 750 rpm. Finally, ethylene at a pressure of 15kg/cm2 was introduced into the reactor to a saturation level in thesolution and the stir rate for the mixture was maintained at 750 rpm.The reaction proceeded for 30 minutes.

[0114] After the completion of the polymerization reaction, the reactionsolution was poured into an acetone solution to precipitate the product.The product was washed with acetone two or three times, filtered, anddried in vacuum oven at 80° C. for 12 hours. The obtained copolymer was43.2 g. The results for this example are shown in Table 4.

EXAMPLES B to F

[0115] The same procedures as described in Example A were repeated toprepare various cycloolefin copolymers except that the reactiontemperature, the metallocene amount, and the MAO amount were changed.The metallocene used in Examples A to F was the same. The resultsobtained are shown in Table 4. TABLE 4 Metallocene Reaction ethyleneComplex MAO Temperature pressure Yield Activity Tg Example (mg) (ml) (°C.) (kg/cm²) (g) (g/gZr · hr) (° C.) A 1 7 100 15 43.2  3.9 × 10⁵ 173 B0.24 1.3 80 15 10.9 2.07 × 10⁵ 163 C 0.23 1.3 100 15 15.3 5.90 × 10⁵ 176D 0.22 1.3 120 15 20.4 8.23 × 10⁵ 185 E 0.23 1.3 140 15 26.4 10.2 × 10⁵195 F 0.24 1.3 155 15 11.1 4.22 × 10⁵ 193

COMPARATIVE EXAMPLE G

[0116] (Compared with Example A)

[0117] Toluene was refluxed in the presence of sodium to remove water toa water content of less than 10 ppm. 500 g of norbornene and 88 g of drytoluene were mixed under nitrogen to obtain an 85 wt % norbornenesolution.

[0118] A 500 ml reactor vessel was heated to 120° C., evacuated for 1hour, and then purged with nitrogen gas three or four times to ensurecomplete removal of moisture and oxygen. Ethylene was introduced intothe reactor to replace nitrogen and expelled. The procedure was repeatedagain. After this, 100 g of the 85 wt % norbornene solution was thencharged in the reactor under a nitrogen atmosphere and the solution wasstirred at a rate of 250 rpm while 4 ml of 1.49 M MAO (methylaluminoxane) was injected into the reactor by a syringe.

[0119] The reactor temperature was adjusted to 100° C. After thetemperature was stabilized, 1 mg ofdiphenylmethylidene(cyclopentadienyl)(9-fluorenyl) zirconium dichloridewas dissolved in 1 ml of toluene in a glove box. Then, 3 ml of MAO wasadded in the metallocene solution for activation. After five minutes ofactivation, the metallocene solution was then injected into the reactorto initiate polymerization and the mixture was stirred at a rate of 750rpm. Finally, ethylene at a pressure of 15 kg/cm² was introduced intothe reactor to a saturation level in the solution and the stir rate forthe mixture was maintained at 750 rpm. The reaction proceeded for 30minutes.

[0120] After the completion of the polymerization reaction, the reactionsolution was poured into an acetone solution to precipitate the product.The product was washed with acetone two or three times, filtered, anddried in vacuum oven at 80° C. for 12 hours. The obtained copolymer was26.9 g. The results obtained are shown in Table 5. TABLE 5 ReactionEthylene MAO (ml)/ Ex- Temperature Pressure 100 ml Activity Tg ample (°C.) (kg/cm²) 85% Nb g/gZr · hr (° C.) G 100 15 7 1.60 × 10⁶ 154 A 100 157 3.90 × 10⁶ 173

EXAMPLES I to K

[0121] The same procedures as described in Example A were repeated toprepare various cycloolefin copolymer having a high Tg except that thereaction temperature was set to 120° C., the reaction time waslengthened to 1 hour, the ethylene pressure was changed, and the amountsof metallocene and MAO were changed. The metallocene used in Examples Ito K was the same as that used in Example A. The results obtained areshown in Table 6. TABLE 6 Metallocene Reaction ethylene Complex MAOTemperature pressure Yield Activity Tg Example (mg) (ml) (° C.) (kg/cm²⁾(g) (g/gZr · hr) (° C.) I 1.05 1.3 120 3 27.4 1.17 × 10⁵ 292 J 0.52 1.3120 5 24.4 2.14 × 10⁵ 245 K 0.55 1.3 120 7 34.9 2.87 × 10⁵ 232

COMPARATIVE EXAMPLE L

[0122] (Compared with Example J)

[0123] Toluene was refluxed in the presence of sodium to remove water toa water content of less than 10 ppm. 500 g of norbornene and 88 g of drytoluene were mixed under nitrogen to obtain an 85 wt % norbornenesolution.

[0124] A 500 ml reactor vessel was heated to 120° C., evacuated for 1hour, and then purged with nitrogen gas three or four times to ensurecomplete removal of moisture and oxygen. Ethylene was introduced intothe reactor to replace nitrogen and expelled. The procedure was repeatedagain. After this, 100 g of the 85 wt % norbornene solution was thencharged in the reactor under a nitrogen atmosphere and the solution wasstirred at a rate of 250 rpm while 4 ml of 1.49 M MAO (methylaluminoxane) was injected into the reactor by a syringe.

[0125] The reactor temperature was adjusted to 100° C. After thetemperature was stabilized, 1 mg ofdiphenylmethylidene(cyclopentadienyl)(9-fluorenyl) zirconium dichloridewas dissolved in 1 ml of toluene in a glove box. Then, 3 ml of MAO wasadded in the metallocene solution for activation. After five minutes ofactivation, the metallocene solution was then injected into the reactorto initiate polymerization and the mixture was stirred at a rate of 750rpm. Finally, ethylene at a pressure of 15 kg/cm² was introduced intothe reactor to a saturation level in the solution and the stir rate forthe mixture was maintained at 750 rpm. The reaction proceeded for 30minutes.

[0126] After the completion of the polymerization reaction, the reactionsolution was poured into an acetone solution to precipitate the product.The product was washed with acetone two or three times, filtered, anddried in vacuum oven at 80° C. for 12 hours. The obtained copolymer was15.3 g. The results obtained are shown in Table 7. TABLE 7 MetalloceneReaction ethylene Complex MAO Temperature pressure Yield Activity TgExample (mg) (ml) (° C.) (kg/cm²) (g) (g/gZr · hr) (° C.) J 0.52 1.3 1205 24.4 2.14 × 10⁵ 245 L 1.00 7 120 5 15.3 9.37 × 10⁴ 199

EXAMPLES M to O

[0127] The same procedures as described in Example A were repeated toprepare various cycloolefin copolymers except that the reactiontemperature was set to 120° C., ethylene pressure was changed, and theamounts of metallocene and MAO were changed. The metallocene used inExamples M to O was the same as that used in Example A. The resultsobtained are shown in Table 8. TABLE 8 Metallocene Reaction ethyleneComplex MAO Temperature pressure Yield Activity Tg Example (mg) (ml) (°C.) (kg/cm³) (g) (g/gZr · hr) (° C.) M 0.22 1.3 120 15 20.4  8.23 × 10⁵185 N 0.49 3.4 120 30 59.0 10.9 × 10⁵ 147 O 0.47 3.4 120 60 52.5 10.0 ×10⁵ 105

EXAMPLES P to S

[0128] The same procedures as described in Example A were repeated toprepare various cycloolefin copolymers except that the reactiontemperature, ethylene pressure, and the amounts of metallocene and MAOwere changed. The metallocene used in Examples P to S was the same asthat used in Example A. The norbornene used had differenceconcentrations in these examples. The results obtained are shown inTable 9. TABLE 9 Metallocene norbornene Reaction ethylene Complex MAOconcentration Temperature pressure Yield Activity Tg Example (mg) (ml)(%) (g/gZr · hr) (° C.) (g) (g/gZr · hr) (° C.) P 0.23 1.3 85 120 1528.5 5.50 × 10⁵ 183 Q 0.22 1.3 50 120 15 30.8 12.4 × 10⁵ 156 R 0.46 5.285 100 60 70.6 1.36 × 10⁵ 103 S 0.47 5.2 50 100 60 33.0 6.30 × 10⁵  66

EXAMPLE T

[0129] The same procedures as described in Example A were employed,except that the metallocene compound used was changed to that preparedfrom Example 5, the reaction temperature was 120° C., the reaction timewas 10 minutes, and Al/Zr in mole was 3000. The results are shown inTable 10.

COMPARATIVE EXAMPLE U

[0130] The same procedures as described in Example T were employed,except that the metallocene compound used was changed to those used inU.S. Pat. No. 5,559,199 (dimethyl silyl-(1-indenyl)-cyclopentadienylzirconium dichloride and U.S. Pat. No. 5,602,219 (isopropenylidenecyclopentadienyl fluorenyl) zirconium dichloride. The results are shownin Table 10. TABLE 10 Ethylene Reaction Norbornene pressure time YieldTg Activity Conversion Catalysts (kg/cm²) (min) (g) (° C.) g/g Zr · hr(%) USP 5,559,199 15 10 4.8 89.66  3.9 E+05 5.1 USP 5,602,219 15 10 23.6159.96 1.92 E+06 25.40 Catalyst 15 10 32.0 186.15 2.59 E+06 36.29prepared in Catalyst Example 5

[0131] It can be seen from Table 10 that compared with the conventionalcatalyst systems, using the catalyst composition of the presentinvention, the obtained cycloolefin copolymer has an increasednorbornene conversion and a substantially increased glass transitiontemperature (Tg), still maintaining high catalytic activity.

POLYMERIZATION EXAMPLE 1

[0132] Synthesis of Ethylene/Norbornene Copolymer

[0133] A 500 ml reactor vessel was purged with nitrogen three or fourtimes. 100 ml of a norbornene solution (85 wt % in toluene) wasintroduced into the reactor vessel under nitrogen. The stirring rate wasadjusted to 250 rpm. Ethylene was introduced into the reactor to replacenitrogen and expelled. The procedure was repeated three times. Afterthis, 2 ml of MAO (1.49 M) was injected into the reactor at 60° C. 0.012of catalyst A [cyclobutylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconium dichloride] prepared from Catalyst Example 6 wasdissolved in 10 ml of toluene in a glove box and 0.4 ml of MAO (1.49 M)was added to 0.9 g of the catalyst solution (2.74×10⁻⁶ mol). After fiveminutes of activation, the catalyst solution (containing MAO) was theninjected into the reactor. When the mixture was heated to the reactiontemperature (100° C.), ethylene at a pressure of 1.0 kg/cm² wasintroduced into the reactor to start polymerization and the stir ratefor the mixture was maintained at 750 rpm. The reaction proceeded for 30minutes.

[0134] After the completion of the polymerization reaction, the reactionsolution was diluted with 100 ml of toluene and then poured into anacetone solution (containing diluted HF) to precipitate the product. Theproduct was washed with acetone two or three times, filtered, and driedin vacuum oven for 12 hours. The obtained copolymer was 26.3 g. Theresults for this example are shown in Table 11.

POLYMERIZATION EXAMPLES 2-3

[0135] The same procedures as described in Polymerization Example 1 wereemployed except that the metallocene catalysts used were changed toCatalyst B[cyclopentylidene(1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)zirconiumdichloride] (0.95 g, 2.74×10⁻⁶ mol) prepared from Catalyst Example 7 andCatalyst C [cycloheptylidene (1-η⁵-cyclopentadienyl)(1-η⁵-indenyl)-zirconium dichloride] (1.0 g, 2.74×10⁻⁶ mol) preparedfrom Comparative Catalyst Example 8 respectively. The results are shownin Table 11.

COMPARATIVE POLYMERIZATION EXAMPLE 4

[0136] The same procedures as described in Polymerization Example 1 wereemployed except that the metallocene catalyst used was changed toCatalyst D [diphenylmethylidene (cyclopentadienyl)(9-fluorenyl)-zirconium dichloride] (1.3 g, 2.74×10 ⁻⁶ mol). The resultsare shown in Table 11.

COMPARATIVE POLYMERIZATION EXAMPLE 5

[0137] The same procedures as described in Polymerization Example 1 wereemployed except that the metallocene catalyst used was changed to 0.97 g(2.74×10⁻⁶ mol) of Catalyst E obtained from Comparative Catalyst Example9 mol). The results are shown in Table 11. TABLE 11 Catalyst (membernumber Polymerization of the Product Activity Tg Example bridging ring)(g) (g/gZr · hr) (° C.) 1 A (four members) 26.3 2.1 × 10⁵ 289.1 2 B(five members) 26.3 2.1 × 10⁵ 288.3 3 C (seven members) 21.5 1.7 × 10⁵285.8 4 D (no ring) 6.9 0.5 × 10⁵ 216.3 5 E (six members) 15.7 1.3 × 10⁵288.3

POLYMERIZATION EXAMPLE 6

[0138] The same procedures as described in Polymerization Example 1 wereemployed except that the reaction temperature was changed to 120° C. andthe reaction pressure was changed to 1.5 kg/cm². The results are shownin Table 12.

POLYMERIZATION EXAMPLES 7-9

[0139] The same procedures as described in Polymerization Example 6 wereemployed except that the metallocene catalysts used were changed toCatalyst B (0.95 g, 2.74×10⁻⁶ mol), Catalyst C (1.0 g, 2.74×10⁻⁶ mol),and Catalsyt E (0.97 g, 2.74×10⁻⁶ mol) respectively. The results areshown in Table 12. TABLE 12 Catalyst (member number Polymerization ofthe Product Activity Tg Example bridging ring) (g) (g/gZr · hr) (° C.) 6A (four members) 33.4 2.7 × 10⁵ 330.2 7 B (five members) 33.6 2.6 × 10⁵317.1 8 C (seven members) 29.4 2.4 × 10⁵ 310.3 9 E (six members) 19.51.6 × 10⁵ 309.9

POLYMERIZATION EXAMPLE 10

[0140] The same procedures as described in Polymerization Example wereemployed except that the reaction time was changed to 20 minutes. Theresults are shown in Table 13.

POLYMERIZATION EXAMPLES 11-13

[0141] The same procedures as described in Polymerization Example 10were employed except that the metallocene catalysts used were changed toCatalyst B (0.95 g, 2.74×10⁻⁶ mol), Catalyst C (1.0 g, 2.74×10⁻⁶ mol),and Catalyst E (0.97 g, 2.74×10⁻⁶ mol) respectively. The results areshown in Table 13. TABLE 13 Catalyst (member number Polymerization ofthe Product Activity Tg Example bridging ring) (g) (g/gZr · hr) (° C.)10 A (four members) 26.0 3.1 × 10⁵ 312.1 11 B (five members) 26.0 3.1 ×10⁵ 307.1 12 C (seven members) 25.7 3.1 × 10⁵ 305.7 13 B (six members)14.6 1.7 × 10⁵ 310.3

[0142] Tables 11-13 compare the polymerization using the catalystcomposition of the present invention and the conventional one. Theinventive catalyst composition includes a metallocene bridged by a four-or five-member ring. The conventional catalyst composition includes ametallocene bridged by a six- or seven-member ring, or bridged by acarbon with no ring. It can be seen from Tables 11-13 that compared withthe conventional catalyst systems, using the catalyst composition of thepresent invention, the obtained cycloolefin copolymer has an increasednorbornene conversion and a substantially increased glass transitiontemperature (Tg), still maintaining high catalytic activity.

[0143] The foregoing description of the preferred embodiments of thisinvention has been presented for purposes of illustration anddescription. Obvious modifications or variations are possible in lightof the above teaching. The embodiments chosen and described provide anexcellent illustration of the principles of this invention and itspractical application to thereby enable those skilled in the art toutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. All suchmodifications and variations are within the scope of the presentinvention as determined by the appended claims when interpreted inaccordance with the breadth to which they are fairly, legally, andequitably entitled.

What is claimed is:
 1. A catalyst composition for preparing an olefin polymer, comprising: (a) a metallocene compound represented by the formula (I)

wherein R¹ can be the same or different and is hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or arylalkyl group having from 1 to 20 carbon atoms, or two adjacent R¹ groups can link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms; R² can be the same or different and has the same definition as R¹; X is carbon, silicon, germanium, or tin; n is 2, 3 or 4; R³ and R⁴ can be the same or different and are hydrogen, halogen, an alkyl, alkenyl, aryl, alkylaryl or arylalkyl group having from 1 to 12 carbon atoms; M is a Group IVB transition metal with an oxidation state of +4; Y is the same or different and is independently an anionic ligand with a −1 valence; and the angle θ formed by the two cyclopentadienyl rings and X is equal to or greater than 100 degrees; (b) an activating cocatalyst of (1) an aluminoxane, (2) a mixture of AlR¹¹R¹²R¹³ and a borate, or (3) a mixture of AlR¹¹R¹²R¹³ and an aluminoxane, wherein R¹¹, R¹², and R¹³ are a C₁₋₂₀ aliphatic group or a C₆₋₁₀ aromatic group.
 2. The catalyst composition as claimed in claim 1, wherein each of R¹ and R² is H, C₁₋₁₀ alkyl, C₁₋₁₀ alkenyl, C₆₋₁₀ aryl, C₇₋₁₀ alkylaryl, or C₇₋₁₀ arylalkyl.
 3. The catalyst composition as claimed in claim 2, wherein each of R¹ and R² is H, methyl, ethyl, propyl, butyl, isobutyl, amyl, isoamyl, hexyl, 2-ethylhexyl, heptyl, octyl, vinyl, allyl, isopropenyl, phenyl, or tolyl.
 4. The catalyst composition as claimed in claim 1, wherein two adjacent R¹ groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms.
 5. The catalyst composition as claimed in claim 4, wherein two adjacent R¹ groups link together with the cyclopentadienyl moiety to which they are attached to form a saturated or unsaturated polycyclic cyclopentadienyl ligand.
 6. The catalyst composition as claimed in claim 5, wherein two adjacent R¹ groups link together with the cyclopentadienyl moiety to which they are attached to form an indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl group.
 7. The catalyst composition as claimed in claim 1, wherein two adjacent R² groups link together with the carbon atoms to which they are attached to form a saturated or unsaturated ring system having from 4 to 20 carbon atoms.
 8. The catalyst composition as claimed in claim 7, wherein two adjacent R² groups link together with the cyclopentadienyl moiety to which they are attached to form a saturated or unsaturated polycyclic cyclopentadienyl ligand.
 9. The catalyst composition as claimed in claim 8, wherein two adjacent R² groups link together with the cyclopentadienyl moiety to which they are attached to form an indenyl, tetrahydroindenyl, fluorenyl or octahydrofluorenyl group.
 10. The catalyst composition as claimed in claim 1, wherein X is carbon.
 11. The catalyst composition as claimed in claim 1, wherein Y is H, a C₁₋₂₀ hydrocarbon group, a halogen, a C₆₋₂₀ aryl group, a C₇-₂₀ arylalkyl group or alkylaryl group, a C₁₋₂₀ alkoxy group, a C₁₋₂₀ aryloxy group, —NH₂, —NHR⁷, —NR⁷R⁸, —(C═O)NH₂, —(C═O)NHR⁹, or —(C═O)NR⁹R¹⁰, and each of R⁷, R⁸, R⁹ and R¹⁰ is a C₁₋₂₀ hydrocarbyl group.
 12. The catalyst composition as in claim 1, wherein Y is a halogen or —N(CH₃)₂.
 13. A process for preparing an olefin polymer, comprising the step of: polymerizing (a) an olefin, or (b) at least one olefin with at least one other monomer, under polymerizing conditions in the presence of a catalytically effective amount of the catalyst composition as claimed in claim
 1. 14. The process as claimed in claim 13, wherein the process comprises polymerizing (a) an olefin, and the olefin is a cycloolefin.
 15. The process as claimed in claim 13, wherein the process comprises polymerizing (b) at least one olefin with at least one other monomer, and wherein the olefin is a cycloolefin and the other monomer is an acyclic olefin.
 16. The process as claimed in claim 15, wherein the cycloolefin is a bicycloheptene, a tricyclodecene, a tricycloundecene, a tetracyclododecene, a pentacyclopentadecene, a pentacyclopentadecadiene, a pentacyclohexadecene, a hexacycloheptadecene, a heptacycloeicosene, a heptacycloheneicosene, a octacyclodocosene, a nonacyclopentacosene, or a nonacyclohexacosene.
 17. The process as claimed in claim 15, wherein the acyclic olefin is ethylene or an β-olefin having 3 to 12 carbon atoms.
 18. The process as claimed in claim 17, wherein the β-olefin is propylene, 1-butene, 1-pentene, 1-hexene, or 1-octene.
 19. The process as claimed in claim 15, wherein the process comprises polymerizing (b) a cycloolefin with an acyclic olefin, and wherein the cycloolefin is norbornene and the acyclic olefin is ethylene.
 20. The process as claimed in claim 15, wherein the olefin polymer resulted has a glass transition temperature ranging from 60° C.-350° C.
 21. The process as claimed in claim 15, wherein the olefin polymer results has a glass transition temperature ranging from 120° C.-350° C.
 22. The process as claimed in claim 15, wherein the olefin polymer results has a glass transition temperature ranging from 250° C.-350° C.
 23. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein R is a C₁-C₂₀ hydrocarbyl group.
 24. The process as claimed in claim 13, wherein the metallocene compound of formula (T) has the structure

wherein R is a C₁-C₂₀ hydrocarbyl group.
 25. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein R is a C₁-C₂₀ hydrocarbyl group.
 26. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein A is halogen.
 27. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein R is a C₁-C₂₀ hydrocarbyl group.
 28. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein R is a C₁₋₂₀ hydrocarbyl group.
 29. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure

wherein A is halogen.
 30. The process as claimed in claim 13, wherein the metallocene compound of formula (I) has the structure 